This invention relates to laser scanning and switching in arrays having large port counts.
Currently, most optical switching is either done by converting the signals into electrical signals, switching, and then back to optical signals or by using MEMS mirrors, or by optoelectronic switches fabricated on lithium niobate. Each of these approaches is either expensive, bulky or complex. 16xc3x9716 switches have been constructed with small volumes, however, the loss was high, and the approach does not scale to larger switch ports. There have been approaches proposed that reduce the scaling from N{circumflex over ( )}2 to NLOG2(N). However, the trade was an extremely large size: a few meters long for a 64xc3x9764.
A common configuration for an optical switch is N input fiber ports and N output fiber ports where N is an integer. This configuration is referred to as an Nxc3x97N optical switch, and it is constructed of approximately N{circumflex over ( )}2 individual (1xc3x972) switches. For example, a 16xc3x9716 has 16 input fibers and 16 output fibers. The problem with the standard approach is that the number of switches increases rapidly as the number of ports, N is increased. The number of switches scales as N{circumflex over ( )}2, and the complexity of the Nxc3x97N switch increases very rapidly. This has prevented large scale, low loss Nxc3x97N switches from being manufacturable in a small package. Commercially available switches with a size of 32xc3x9732 or larger, are large, rack mounted systems. 16xc3x9716 switches have been fabricated using integrated optical approaches such as lithium niobate or glass, however they have relatively high loss, and it is not feasible to scale them to larger size with low loss.
The present invention relates to a method and a device that allows for switching N by N optical paths, each path being non-blocking; an optical switch where the various optical beams are steered by movement of their corresponding lenses. An optical switch is much more compact, lighter and dissipates less power compared to an electrical switch. The optical switch also can route orders of magnitude higher data rate signals. Moreover, all optical-to-optical switches currently under development employ reflective surfaces, such as MEMS micro-mirrors. In contrast, the present invention uses a refractive approach, where the laser beam is scanned using moving lenses.
The present switch has a much improved scalability compared to other approaches. The number of individual switches required scales linearly in the port count N. This permits an extremely large port count with Nxc3x97N exceeding 1000xc3x971000.